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Motivation RCRA requires TSDs to determine whether they are located in 100-year floodplains Additional engineering studies are required if TSD is located in a floodplain ($$) Floodplain extent is influenced by losses Stream “loss” is groundwater “gain” Stream channel losses can be pathways for subsurface contaminant transport

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Meanwhile, back at the river… Streamflow Losses on Big Lost River were determined from stream gage station data by Bennett (1990) Average annual streamflow: 1965 to 1987 Sixteen (16) streamflow measuring sites and stations

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Specifics at Station 11 Coarse pebble to cobble gravel above gaging station 11 Sediment grades to sand and “sandy silt” below station 11 Sandy Loam set of Green-Ampt parameters was used for “sandy silt”

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Conclusions Green-Ampt parameters developed by Rawls and Brakensiek may be a useful tool to determine stream channel infiltration loss rates. Ten-hour Modeled Infiltration Rate (1.6 cm/hr) approximated the measured infiltration rate (1.0 cm/hr) Time frame of measured infiltration rate was not specified. Compare field samples with R-K parameters This is a research area worth further investigation.